Scientists say they may be able to develop treatments for children with Down's syndrome after the discovery of earliest developmental changes that lead to the illness.

A team of researchers from Barts and the Royal London have found the earliest developmental changes in embryonic stem cells caused by an extra copy of human chromosome 21 that sets off a chain of genetic changes in the developing embryo which results in the condition.

Lead researcher Dean Nizetic, Professor of Cellular and Molecular Biology at Barts and The London School of Medicine and Dentistry, utilized embryonic stem cells from a previously genetically engineered species of mice carrying a copy of human chromosome 21.

Nizetic added that further research is needed in this field which might lead to clues for the design of new therapeutic approaches tackling developmental delay, mental retardation, ageing and regeneration of brain cells, and Alzheimer's disease.

Down syndrome is a condition in which extra genetic material causes delays in the way a child develops, both physically and mentally. Despite their challenges, kids with Down syndrome can go to regular schools, make friends, enjoy life, and get jobs when they're older.

The study is published in the American Journal of Human Genetics.